Integrated gas panel apparatus is to control and finally to mix flow of several different kinds of gas used for manufacturing semiconductor devices and to supply them to a chamber. The integrated gas panel apparatus has been developed in order to shorten a gas supply control line comprising a piping structure arranged on the downstream side of the chamber. More concretely, as one example is shown in the patent document 1, a gas control unit such as a valve or a mass flow controller is mounted on a panel body generally of a plate shape. Inside the panel body are formed, for example, multiple branch flow channels on which the above-mentioned gas control unit is mounted and a single main flow channel with which the branch flow channels are connected and into which each gas flowing in the branch flow channels joins.
Various improvements have been carried out to the integrated gas panel apparatus, there is an integrated gas panel apparatus having an arrangement of the panel bodies by appropriately connecting various kinds of block bodies so as to construct a flexible flow channel to cope with various kinds of gas to be used.    Patent document 1: Japan patent laid-open number 10-169881